What do I do when my body can't handle labor work anymore?

Twenty years of this work, and your body is sending the bill, and you are scared of what you will do when it finally gives out. That fear is not weakness. It is honesty. You know your own body better than anyone, and it is telling you the truth about a limit that is coming. The good news hidden in that fear is that it came with a warning, which means you still have time to plan. Twenty years built more than sore joints. You have judgment, know-how, and the respect of people who have watched you work. Those can move into roles your body will tolerate: supervising, training, estimating, inspecting, teaching the ones coming up behind you. The knowledge in your head outlasts the strength in your back. Do not wait for the day it gives out to start. Pick one step now, while the choice is still yours. Learn the office side, get a certification, mentor a younger worker, ask your employer about a role off the tools. You spent twenty years being the one who could be counted on. Point that same grit at your next chapter, and it will hold you up again.